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I have a MacBook set up with Boot Camp, and the XP partition is NTFS. The split is 50-50 and there is no unallocated space on the hard drive.

I want to create a shared 50GB FAT32 partition for my DropBox files, so regardless of which OS I boot into, I only have to keep one copy of my DropBox on the laptop shared between the two OS.

So my question is how do I create this new partition without starting fresh? I would assume I do it from OS X?

Thanks Tom

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can't your OSX install access your NTFS partition? just keep your Dropbox files on the NTFS. – quack quixote Oct 10 '09 at 16:49
Related question:… – Canadian Luke Jul 27 '12 at 19:56
up vote 6 down vote accepted

Mac OS X can both read and write to NTFS partitions. Reading is native; writing can be enabled by installing MacFuse and ntfs3g, both free, open-source, stable projects.

This should save you the need to repartition. It's easier, safer and faster.

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Thanks for these pointers, I'm going to give that a go now... – tomfanning Oct 11 '09 at 12:44

Disk utility in OSX can dynamically resize Mac OSX filesystems. It cannot resize NTFS partitions. Also - in Bootcamp 3.0 ( the one that comes with Snow Leopard ) OSX partitions are visible from Windows .

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I have just purchased a MBA and I have managed to get a shared partition working, although it took me a number of times to get it right.

As I have the Air, I followed the instructions here to get started with Windows on Mac without a DVD drive.

The standard Boot Camp installation only allows the hard drive to be split in two. After running the Boot Camp Assistant fire up Disk Utility, delete the newly created BOOTCAMP partition. Create 2 new partitions, with the 'middle' one being the shared partition. I used exFAT as the format, so I can have files over 4Gb. Use FAT32 for the 'end' partition, as the same as Boot Camp creates, although that will just get formatted as NTFS by the Windows installer anyway.

I also called the end partition 'BOOTCAMP', but I'm not sure if that is required. Apparently you need to make the last partition the Windows partition, although I haven't verified that either. Basically I have done this once and it works so I'm not going to format my drive again just to make sure :)

After that is done, restart and go into the Windows installer. From there select the 'last' partition (should be partition 4), format it with NTFS and then it should work as expected.

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(Note: Answer was originally written a few years ago before I owned my own Mac instead of just using one at work. Edited.)

I know that PartitionMagic for Windows can do resizing of NTFS. OS X can not resize the partition it's running on, and I am not even sure if its "Split" feature DOESN'T actually destroys data (I think it does). It can't resize NTFS though.

Third option is GPartEd live CD (as opposed to PartitionMagic, free by price, but also free-as-in-free-speech) which should be able to resize NTFS and HFS+. On the other hand, it appears to have no recovery facilities so if OS crashes or you lose power, the partition is most likely destroyed -- PartitionMagic's recovery has saved data on my external HDD once, when someone unplugged it while PM was running.

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either of these options will work but will be veerry slooow. – quack quixote Oct 10 '09 at 16:46
I created a 50GB FAT32 partition with gparted's live CD (after resizing the other two partitions on the drive) and unfortunately now my Windows partition isn't visible when holding down the option key at boot to get the dual-boot menu. Fortunately it is a fresh installation of Windows so nothing lost... – tomfanning Oct 11 '09 at 12:43
OSX can resize it's own partition – Canadian Luke Jul 27 '12 at 19:56

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